1. Field of the Invention
The present invention relates to a gas sensor unit and a method of forming the same. More particularly, the present invention relates to a low cost and highly sensitive gas sensor unit, and a method of forming the same.
2. Description of Related Art
In order to prevent the leakage of various toxic, flammable, explosive, or dangerous gases used or produced during industrial processes, which is harmful to human beings and causes great damage to the environment, recently, a sensor capable of detecting various gas molecules was developed and it has attracted the attention from all circles. Such gas sensor has featured high sensitivity, low cost, good selectivity, rapid response, high stability, reproducibility, and so on.
Presently, the gas sensors generally available include catalyst combustion type, metal semiconductor absorption type and conductive polymer material type, and so on. However, all the current gas sensor materials, such as in the catalyst combustion type or metal oxide absorption type gas sensor, commonly used for gases like alcohols need to be operated at high temperature, so that the detection application thereof for flammable gases are limited.
Since the conductive polymer material has a single/double alternating conjugated bond, due to the specific electron configuration thereof, the electrons can hop along the molecular chain or across the molecular chain after being oxidized or reduced, so that the material is conductive. Therefore, the material can be used to sense gas at ambient temperature.
However, in the current study concerning a gas sensor of the conductive polymer material, only polypyrrole (PPy) has been studied. Presently, PPy has no commercial application, since it is expensive and the source thereof is not readily available.